how to fix P0420 code on Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the pre-catalytic and post-catalytic oxygen sensors using the O2 sensor socket.
• Inspect the wiring and connectors for damage; replace if necessary.
• Install the new oxygen sensors and torque to manufacturer's specification (typically around 30 lb-ft).

3. Examine and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if needed)
• Raise the vehicle and secure it on jack stands.
• Remove any heat shields or covers obstructing access to the catalytic converter.
• Detach the exhaust pipes connected to the catalytic converter; use an exhaust pipe cutter if necessary.
• Remove the catalytic converter from its mounting brackets.
• Install the new catalytic converter, ensuring proper alignment with the exhaust system.
• Reattach any heat shields and secure all connections.

4. Reset the PCM

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the PCM.